Lines including Saga have also adapted upcoming Scotland-bound itineraries after MSC Virtuosa was denied the right to dock by Scottish authorities last week. 

A Scottish government spokesperson said the decision had made due to the rise in cases of the new Delta variant of Covid-19 and was informed by "the combination of risks that exist between both cruises and the wider travel context".

These, the spokesperson said, included the current trajectory of Covid infections and the "unknowns around the new Delta variant", as well as the "potential for high risk of uncontained rapid transmission on the cruise".

The decision has effectively banned cruise calls in Scotland until the entire country can be placed under the government’s lowest Covid protection level.

A Celebrity spokesperson said: “As we await the next update from the Scottish Government regarding the resumption of cruise visits to Scotland, we have made the decision to change the itinerary of our first Celebrity Silhouette sailing which was due to stop in Greenock on 6 July. 

“In place, we have added two new ports to the itinerary – Liverpool and Dover – offering even more chance for our guests to enjoy the stunning culture and scenery our beautiful country has to offer.”